WHAT does the provider do when it sets the Internet speed for us?

Question

Computer networks

Hello.
Tell me, what does the provider do when we increase our tariff plan and its speed?
What influences that our Internet will become faster?
And how does it depend on our cable, which is hundreds of years old and has not changed, what is the maximum transmission speed it can do if the provider did not limit the Internet speed to us?

Answer 1

the provider counts the amount of traffic transmitted to and from you. everything that exceeds the speed set for the tariff is "dropped", packets are discarded and do not reach the recipient.
an ordinary ancient LAN cable with 4 cores allows you to set the speed up to 100 Mbps (12 Mbps)
if all 8 cores are connected, then up to 1 Gbps (120 Mbps)